{
  "id": "morse",
  "revision": 1,
  "supply_v": 5,
  "measured": false,
  "spice_simulated": false,
  "pcb_qualified": false,
  "sources": [
    {
      "title": "Texas Instruments NE555 — SLFS022K, March 2026",
      "url": "https://www.ti.com/lit/ds/symlink/ne555.pdf"
    },
    {
      "title": "Texas Instruments LM386 — SNAS545D, August 2023",
      "url": "https://www.ti.com/lit/ds/symlink/lm386.pdf"
    },
    {
      "title": "onsemi 2N3904 — NPN transistor",
      "url": "https://www.onsemi.com/download/data-sheet/pdf/2n3904-d.pdf"
    }
  ],
  "accessories": [
    {
      "ref": "BOARD",
      "quantity": 1,
      "value": "PDIP8",
      "text_key": "part_board"
    },
    {
      "ref": "SUPPLY",
      "quantity": 1,
      "value": "5.00 V",
      "text_key": "part_bench"
    },
    {
      "ref": "TEST",
      "quantity": 1,
      "value": "DMM / ×10",
      "text_key": "part_instruments"
    },
    {
      "ref": "RTEST",
      "quantity": 1,
      "value": "8.2 Ω / 1% / ≥1 W",
      "text_key": "part_testload"
    }
  ],
  "test_points": {
    "TP0": "GND",
    "TP1": "V5",
    "TP2": "TIMING",
    "TP3": "OUT",
    "TP4": "RESET",
    "TP5": "AUDIO_IN",
    "TP6": "AMP_DC",
    "TP7": "SPEAKER_AC"
  },
  "assembly_keys": [
    "assembly_1",
    "assembly_2",
    "assembly_3",
    "morse_assembly_1",
    "morse_assembly_2",
    "assembly_6"
  ],
  "testing_keys": [
    "test_1",
    "morse_test_1",
    "morse_test_2",
    "morse_test_3",
    "test_5"
  ],
  "troubleshooting_keys": [
    "diag_supply",
    "diag_pinout",
    "morse_diag_1",
    "morse_diag_2",
    "diag_noise"
  ],
  "components": [
    {
      "ref": "J1",
      "type": "connector",
      "value": "5 V DC",
      "pins": {
        "1": "V5",
        "2": "GND"
      },
      "text_key": "part_supply",
      "quantity": 1
    },
    {
      "ref": "U1",
      "type": "ic",
      "value": "NE555P",
      "pins": {
        "1": "GND",
        "2": "TIMING",
        "3": "OUT",
        "4": "RESET",
        "5": "CONTROL",
        "6": "TIMING",
        "7": "DISCHARGE",
        "8": "V5"
      },
      "text_key": "part_555",
      "quantity": 1
    },
    {
      "ref": "CDEC",
      "type": "capacitor",
      "value": "100 nF / 16 V",
      "pins": {
        "1": "V5",
        "2": "GND"
      },
      "text_key": "part_decouple",
      "quantity": 1
    },
    {
      "ref": "CBULK",
      "type": "capacitor",
      "value": "47 µF / 16 V",
      "pins": {
        "+": "V5",
        "-": "GND"
      },
      "text_key": "part_bulk",
      "quantity": 1
    },
    {
      "ref": "CCONT",
      "type": "capacitor",
      "value": "10 nF / 16 V",
      "pins": {
        "1": "CONTROL",
        "2": "GND"
      },
      "text_key": "part_control",
      "quantity": 1
    },
    {
      "ref": "RRESET",
      "type": "resistor",
      "value": "1 kΩ / 0.25 W",
      "pins": {
        "1": "V5",
        "2": "RESET"
      },
      "text_key": "part_reset",
      "quantity": 1
    },
    {
      "ref": "RA",
      "type": "resistor",
      "value": "4.7 kΩ / 1%",
      "pins": {
        "1": "V5",
        "2": "DISCHARGE"
      },
      "text_key": "part_ra",
      "quantity": 1
    },
    {
      "ref": "RB",
      "type": "resistor",
      "value": "6.8 kΩ / 1%",
      "pins": {
        "1": "DISCHARGE",
        "2": "RHEOSTAT"
      },
      "text_key": "part_rb",
      "quantity": 1
    },
    {
      "ref": "RV1",
      "type": "potentiometer",
      "value": "10 kΩ / LIN",
      "pins": {
        "A": "RHEOSTAT",
        "W": "TIMING",
        "B": "TIMING"
      },
      "text_key": "part_rheostat",
      "quantity": 1
    },
    {
      "ref": "CT",
      "type": "capacitor",
      "value": "68 nF / 16 V",
      "pins": {
        "1": "TIMING",
        "2": "GND"
      },
      "text_key": "part_ct_film",
      "quantity": 1
    },
    {
      "ref": "RBASE",
      "type": "resistor",
      "value": "3.9 kΩ / 0.25 W",
      "pins": {
        "1": "V5",
        "2": "KEY_BASE"
      },
      "text_key": "part_key_base",
      "quantity": 1
    },
    {
      "ref": "Q1",
      "type": "npn",
      "value": "2N3904",
      "pins": {
        "E": "GND",
        "B": "KEY_BASE",
        "C": "RESET"
      },
      "text_key": "part_transistor",
      "quantity": 1
    },
    {
      "ref": "KEY1",
      "type": "switch",
      "value": "NO",
      "pins": {
        "1": "KEY_BASE",
        "2": "GND"
      },
      "text_key": "part_key",
      "quantity": 1
    },
    {
      "ref": "CIN",
      "type": "capacitor",
      "value": "100 nF / film / 16 V",
      "pins": {
        "1": "OUT",
        "2": "AUDIO_AC"
      },
      "text_key": "part_cin",
      "quantity": 1
    },
    {
      "ref": "RPAD",
      "type": "resistor",
      "value": "100 kΩ / 1%",
      "pins": {
        "1": "AUDIO_AC",
        "2": "PAD"
      },
      "text_key": "part_pad",
      "quantity": 1
    },
    {
      "ref": "RSH",
      "type": "resistor",
      "value": "2.2 kΩ / 1%",
      "pins": {
        "1": "PAD",
        "2": "GND"
      },
      "text_key": "part_shunt",
      "quantity": 1
    },
    {
      "ref": "RV2",
      "type": "potentiometer",
      "value": "10 kΩ audio",
      "pins": {
        "A": "PAD",
        "W": "AUDIO_IN",
        "B": "GND"
      },
      "text_key": "part_volume",
      "quantity": 1
    },
    {
      "ref": "U2",
      "type": "ic",
      "value": "LM386N-1",
      "pins": {
        "1": "NC_GAIN1",
        "2": "GND",
        "3": "AUDIO_IN",
        "4": "GND",
        "5": "AMP_DC",
        "6": "V5",
        "7": "BYPASS",
        "8": "NC_GAIN8"
      },
      "text_key": "part_386",
      "quantity": 1
    },
    {
      "ref": "CADEC",
      "type": "capacitor",
      "value": "100 nF / 16 V",
      "pins": {
        "1": "V5",
        "2": "GND"
      },
      "text_key": "part_amp_decouple",
      "quantity": 1
    },
    {
      "ref": "CABULK",
      "type": "capacitor",
      "value": "220 µF / 16 V",
      "pins": {
        "+": "V5",
        "-": "GND"
      },
      "text_key": "part_amp_bulk",
      "quantity": 1
    },
    {
      "ref": "CBYP",
      "type": "capacitor",
      "value": "10 µF / 16 V",
      "pins": {
        "+": "BYPASS",
        "-": "GND"
      },
      "text_key": "part_bypass",
      "quantity": 1
    },
    {
      "ref": "RZ",
      "type": "resistor",
      "value": "10 Ω / 0.25 W",
      "pins": {
        "1": "AMP_DC",
        "2": "ZOBEL"
      },
      "text_key": "part_zobel_r",
      "quantity": 1
    },
    {
      "ref": "CZ",
      "type": "capacitor",
      "value": "47 nF / 16 V",
      "pins": {
        "1": "ZOBEL",
        "2": "GND"
      },
      "text_key": "part_zobel_c",
      "quantity": 1
    },
    {
      "ref": "COUT",
      "type": "capacitor",
      "value": "220 µF / 16 V",
      "pins": {
        "+": "AMP_DC",
        "-": "SPEAKER_AC"
      },
      "text_key": "part_cout",
      "quantity": 1
    },
    {
      "ref": "SP1",
      "type": "speaker",
      "value": "8 Ω / ≥1 W",
      "pins": {
        "1": "SPEAKER_AC",
        "2": "GND"
      },
      "text_key": "part_speaker",
      "quantity": 1
    }
  ],
  "formulas": [
    "f ≈ 1.44 / [(RA + 2 RBtotal) CT]",
    "RA = 4.7 kΩ; RBtotal = 6.8…16.8 kΩ; CT = 68 nF",
    "f ≈ 553…1157 Hz; DH ≈ 56.1…62.8%",
    "Rload ≈ 2.2 kΩ ∥ 10 kΩ ∥ 50 kΩ; RPAD = 100 kΩ; Av ≈ 20",
    "IC ≤ 5 mA + 1.5 mA; IB ≥ (5 − 0.85)/3.9 kΩ",
    "PTEST = VRMS² / 8.2 Ω; VRMS ≤ 1 V → PTEST ≤ 0.122 W"
  ],
  "schematic_height": 1825
}